Medical device manufacturing method and medical device assembly

ABSTRACT

A medical device in which a part to be secondarily shaped comprises a molded silicone rubber article is subjected to heatless shaping by irradiation with electron-rays. The irradiation with electron-rays enables shaping and, furthermore, sterilization under some conditions. In a medical device comprising a part in which at least a silicone rubber is used and the mechanical properties of the silicone rubber preferentially appear, the shape of the above-described part upon molding is deformed with the use of a correcting member to a level exceeding the desired deformed shape and maintained in this state. Next, electron-ray irradiation is conducted in this state and then the correcting member is eliminated. Thus, the desired deformed shape intermediate between the shape upon the molding and the shape upon the electron-ray irradiation can be obtained.

This application is a divisional of U.S. application Ser. No. 12/890,865filed on Sep. 27, 2010, which is a continuation of InternationalApplication No. PCT/JP2009/055960 filed on Mar. 25, 2009, and claimspriority to Japanese Application No. 2008-084232 filed on Mar. 27, 2008,the entire content of all three of which is incorporated herein byreference.

TECHNICAL FIELD

The present invention generally pertains to a medical device. Morespecifically, the invention relates to a medical device having aninsertion part configured to be inserted into a body cavity such as ablood vessel, a digestive canal, a bile duct or the like, with theinsertion part being formed of silicone rubber into a fixed shapesuitable for the insertion by use of an electron beam.

In general, the insertion part of the medical device is a tube orrod-like elongate body and uses the tube whose portion, e.g., distal endis shaped in angular fashion, such as in arcuate, wavy, dogleg, orL-shaped fashion. This shaping is performed by electron beamirradiation.

In particular, the medical device and method disclosed here allow forshape-fixation of the medical device concurrently with electron beamsterilization.

BACKGROUND DISCUSSION

Generally, a body cavity insertion device such as a catheter or the likeis such that recently electron beam irradiation has attracted attentionin view of an installation aspect and management aspect as well as aneasy handling aspect in place of EOG (ethylene oxide gas) sterilizationbefore use.

A silicon rubber tube and radioactive sterilization of such tube areknown from Japanese Patent Laid-open No. Hei 4-371157. If silicon tubesthat are twice-folded or four-times folded and packaged are sterilized,a phenomenon often occurs in which the silicon tubes adhere to eachother. For this reason, it is considered that the radioactiveirradiation cannot be used for tube sterilization. To solve such aproblem, unpackaged tubes are previously irradiated with a radioactivebeam such as an electron beam before sterilizing the packaged tubes. Inthe previous irradiation, tubes are put in a previous-irradiation trayprovided inside with partitions or the like to prevent the tubes fromcoming contacting each other. Then, a radioactive ray irradiation deviceis used to emit radioactive rays to the tray to apply an energy of 2.5to 20 Mrad thereto. This removes the residual monomer and oligomer forstabilization and thereafter sterilization is performed. At the time ofthe sterilization, even use of radioactive rays can prevent the silicontubes from adhering to each other. Japanese Patent Laid-open No. Hei4-371157 discloses that at the time of the sterilization, electron beamsare directed, particularly, to the two-folded or four-folded silicontubes, i.e., to the silicon tubes in contact with each other.

Tubes that are inserted and indwelled into a blood vessel, a digestivecanal or a ventral cavity may use silicone rubber chemically stable andsuperior in chemical resistance in some cases. However, the siliconerubber is not a thermoplastic resin and so posterior processing such asangular-shaping may be difficult to pursue periphery-reachingperformance. Generally, the shaping of medical tubes includesinjection-molding silicone rubber by use of a mold with a predeterminedshape, and deforming an extruded tube into a predetermined shape andthen subjecting the deformed tube to heat fixation.

The present inventors started a study while considering that a reductionin step and time and simplification of an installation can be achievedif sterilization of a medical device using silicone rubber byradioactive ray irradiation and shaping of the medical device can beperformed simultaneously with each other.

Japanese Patent Laid-open No. Hei 4-371157 describes only thatradioactive rays are emitted two times in order to prevent the adhesionof silicone rubber tubes and to sterilize them and that the tubes arefour-folded for sterilization. However, Japanese Patent Laid-open No.Hei 4-371157 nowhere discusses performing intentional shaping and usingan electron beam irradiation technique for the same.

Japanese Patent Laid-open No. Hei 4-371157 mentions that what can beemitted to the silicon tube may be not only electron beams but alsoradioactive rays.

The inventors first deformed silicone rubber in a forcible manner andemitted gamma beams to the silicone rubber remaining deformed. However,after removing the forcible manner of deformation, the silicone rubberreturned to the shape before the irradiation.

The inventors next deformed silicone rubber in a forcible manner andemitted electron beams to the silicone rubber remaining deformed. Inthis case, upon removing the forcible manner of deformation, theinventors discovered that the silicone rubber remained deformed. In thisway, the inventors developed the medical device and method disclosedhere.

A medical device whose portion to be shaped is made of a silicone rubbermolded article could not be stably shaped through use of a heatingdevice. EOG (ethylene oxide gas) sterilization, which represents onesterilization not utilizing heat, raised a concern about an influence ofresidual gas on a living body. To eliminate the concern, the portion tobe shaped was irradiated with gamma beams and electron beams for shapingwithout heating. In this case, it has been found that the portion to beshaped is not shaped by gamma beams but can be shaped and alsosterilized by electron beams depending on conditions.

SUMMARY

One aspect disclosed here involves a medical device assembly with amedical device having a predetermined shape portion which uses at leastsilicone rubber, and in which a property of the silicone rubberpreferentially appears and which results from being subjected toelectron beam irradiation, wherein a correcting member which is formedof a material not adhering, sticking or cross-linking to the siliconerubber due to contact therewith, and which has a shape-giving shapefurther deformed from a predetermined shape of the predetermined shapeportion, is in contact with the medical device, and in this contactstate, the medical device which is subjected to electron beamirradiation and from which the correcting member is removed has thepredetermined shape different from a shape in a free state duringelectron beam non-irradiation.

The correcting member can be a shaped (inclusive of wire-like) body orrod (inclusive of rod-like) body.

The correcting member can be a shaped cylindrical body or groove.

The correcting member can be part of a packaging body of the medicaldevice. The packaging body can include a tray, a case, a bag, etc, withthe correcting body being a part of a tray, for example, and the partworks a portion for holding the medical device (e.g., a channel, a dent,a protuberance). The medical device and correcting body can be packagedtogether or the correcting body can be packaged by itself.

The electron beam irradiation is preferably performed to sterilize themedical device.

The shape of the predetermined shape portion is preferably a tube or acylindrical body.

The shape of the predetermined shape portion is an elongate body such asa wire-like body or a rod-like body.

According to another aspect, a medical device assembly comprises: amedical device possessing a predetermined portion comprising siliconerubber, where the predetermined portion possesses a first shape and isadapted to be electron beam irradiated to change the first shape of thepredetermined portion and cause the predetermined portion to possess apredetermined shape; and a correcting member configured to contact thepredetermined portion of the medical device to form a medical deviceassembly which is subject to the electron beam irradiation. Thecorrecting member is formed of a material which does not stick, adhereor cross-link to the silicone rubber when the correcting member contactsthe medical device, wherein the correcting member possesses ashape-giving shape which alters the first shape of the predeterminedportion of the medical device when the correcting member contacts thepredetermined portion so the predetermined portion of the medical deviceexhibits a second shape different from the first shape, with thecorrecting member being moved out of contact with the predeterminedportion of the medical device after the electron beam irradiation,whereupon the predetermined portion of the medical device possesses thepredetermined shape which is different from the first shape and thesecond shape.

A medical device in which at least a portion using silicone rubber ismolded into a predetermined shape by electron beam irradiation, whereina correcting member which does not adhere, stick or cross-link to thesilicone rubber in a contact state with the silicone rubber, and whichholds the medical device in a bending state greater than a bending stateof the predetermined shape, and the medical device constitutes a medicaldevice assembly, and the medical device assembly is subjected to aprocessing amount of electron beam irradiation.

Utilizing the disclosure here, it is possible to impart a shape to asilicone rubber molded article by posterior processing, with onlymodifying the shaping step being required. Therefore, the step isrelatively simple, a variety of shapes can be enabled, and costs can bereduced.

Also sterilization can be performed depending on a dose of electronbeam, which not only can reduce steps and time but also electron beamirradiation is required only one time. Thus, economic efficiency isrelatively high.

The medical tube disclosed here does not keep or maintain the shapeproduced when the tube is molded, but a shape between the shape producedwhen the tube is molded and a corrected shape. Therefore, the deformedprocess portion keeps its shape under a delicate balance betweenextension and compression, and is responsively varied by delicateexternal force to undergo restoring force. Thus, it is superior inperiphery-reaching performance into a body cavity because it exhibitssoftness.

BRIEF DESCRIPTION OF DRAWING FIGURES

FIG. 1 is a plan view of a medical device and correcting member togetherforming a medical device assembly before the correcting member isbrought into contact with the medical device.

FIG. 2 is a plan view of the medical device and correcting membertogether forming a medical device assembly after the correcting memberis brought into contact with the medical device.

FIG. 3 is a plan view of the medical device after the correcting memberis moved out of contact with the medical device.

DETAILED DESCRIPTION

The disclosure here relates to shape-fixation of a medical device usedin a structure by electron beam irradiation, and shape fixation of asilicone rubber portion by electron beam irradiation, wherein theproperties of the silicone rubber are exhibited. To provide an exampleof this reference to the properties of the silicone rubber beingexhibited, if the silicone rubber is used together with, for example, arelatively thick or large dimensioned metal wire (e.g., a wire made oftitanium), the shape of the composite article (the silicone rubber andthe metal wire) depends on the shape of the metal wire because it is theproperties of the metal wire which exhibit themselves. On the otherhand, if the silicone rubber is used together with, for example, arelatively thin or small dimensioned metal wire, the shape of thecomposite article depends on the shape of the silicone rubber becausethe properties of the silicone rubber preferentially appear or exhibitthemselves. The method disclosed here is useful in shaping hollow distaltips of catheters such as a urinary catheter, a peritoneal catheter, afeeding catheter, a venous catheter and the like, shaping of a bloodvessel model (a blood vessel model used to, for example, to practicesurgery), forming a complicated blood vessel path, appropriately formingor configuring a balloon to effect the folding tendency of the balloon,and shaping the distal tip of a solid rod such as a guide wire and acatheter of a ultrasonograph.

The structure which uses silicone rubber and in which the properties ofsilicone rubber preferentially appear here is a multilayered body madeof silicone rubber and other resin or thin film metal if the structureis a hollow body like a tube. In addition, the structure is such that alayer other than the silicone rubber layer is very thin and theproperties of the silicone rubber are dominant. Even if the structure isa rod-like body and the front surface of the rod-like body of siliconerubber is formed of resin or a metal thin layer which is anothermaterial, it needs only the properties of silicone rubber appearing.

Silicone rubber used here has a Shore A hardness of 15 to 80 beforeelectron beam irradiation. Generally speaking, if the silicone rubberhas a Shore A hardness less than 15, it is difficult to shape because itis too soft, and if the Shore A hardness exceeds 80, such siliconerubber is not preferable because a distal end to be inserted into a bodycavity is too hard in relation to the hardness after shaping.

Silicone rubber increases in hardness after electron beam irradiation.Respective pieces of silicone rubber having Shore A hardness of 20(NuSil LLC., silicon MED-4020), 35 (the same company, silicon MED-4035)and 50 (the same company, silicon MED-4050), which have equal intervalstherebetween, before irradiation, are increased to approximately 12, 8and 6 in hardness after irradiation with the same dose as they havelower hardness. Therefore, if the change in hardness is emphasized orimportant (i.e., if a relatively smaller change in hardness afterelectron beam irradiation is desired), a silicone rubber can be selectedwhich has a hardness of 35 or greater to achieve a relatively smallerchange in hardness upon electron beam irradiation. The hardness ofsilicone rubber can be adjusted by the dose of radiation.

Preferably, the silicone rubber shaped after electron beam irradiationhas a Shore A hardness of 25 to 90. Generally speaking, silicone rubberhaving a Shore A hardness of less than 25 is not preferred because ofrelatively poor shape-maintaining performance during use. In addition,silicone rubber having a Shore A hardness in excess of 90 is notpreferable because it is too hard as a distal end to be inserted into abody cavity.

If silicone rubber is formed in a hollow manner, a correcting member asa shaping jig needs to be formed of a material that does not adhere to,stick to or cross-link to the silicone rubber upon contact therewith andthat exhibits a shape-giving shape further deformed in excess of thepredetermined shape. That is, if it is desired that the medical device,following electron beam irradiation, possesses a predetermined shape,the correcting member used with the silicone rubber medical shouldpossess or exhibit a shape-giving shape that exceeds the predeterminedshape. By way of example, to produce a silicone rubber medical devicepossessing, after electron beam irradiation, a predetermined shapeinvolving a bend portion bent at a first angle, the correcting membershould possesses a shape (shape-giving shape) having a bend portion bentat a second angle greater than the first angle. In this way, after thecorrecting member is removed from the medical device following electronbeam irradiation, the medical device will exhibit the predeterminedshape having the bend portion bent at the first angle. A groove isformed of polypropylene, polyethylene, polystyrene or the like tocorrespond to the shape-giving shape and the silicone rubber formed in ahollow manner is received in the groove. In this way, electron beamirradiation can be performed thereon.

In a preferred embodiment, the electron beam irradiation is performedwhile a wire-like body, such as wire, easily subjected to bending, or arod-like body, is inserted into the hollow portion.

The wire-like body and the rod-like body can be metal bodies such asiron, stainless steel, copper, aluminum, etc. Preferably, the frontsurface of the wire-like body or the rod-like body is subjected tosilver plating, PTFE coating, or other processing so as to make it easyfor the wire-like body or the rod-like body to be removed from thehollow portion after the shaping by the electron beam irradiation. Inaddition, such coating produces an effect of inhibiting or preventingthe corrosion of the correcting member per se.

The correcting member used here may possess a previously impartedshape-giving shape or the correcting member used here may be deformedinto the shape-giving shape after being combined with the medical deviceto be shaped.

Preferably, a correcting member as a shaping jig used when siliconerubber is formed in an elongate body such as a rod-like body or awire-like body is a body having a groove or a cylindrical body such as atube that is plastically deformed by external force and maintains theshape after the removal of the external force. If the correcting memberis a tube, a rod-like body of silicone rubber is inserted into the tubeto deform it and the maintaining force of the tube maintains thedeformation. Alternatively, an auxiliary means can be used to preventthe restoration of the tube. The tube may be previously shaped. If thecorrecting member is a groove, the groove is previously formed into ashaping-shape. The rod-like body is received in the groove while beingbent. In this case, preferably, the rod-like body is inserted into aremovable cylindrical body or received in the groove. Further, thecylindrical body or groove as a jig may be part of a packaging body oranother separate from the packaging body. In this case, after thepackaging, electron beam irradiation can concurrently performsterilization and shape-fixation. If the jig is part of the packagingbody, it is possible to concurrently remove also the jig when thepackage is opened for use.

Irradiation energy of electron beams used to process the medical devicedisclosed here needs sufficient intensity so it can pass through thedevice to be irradiated. The irradiation energy may thus be 1 to 10 MeV,preferably, 5 to 10 MeV. An irradiation dose of a predetermined amountof electron beams used to process the medical device may be 1 to 100kGy, preferably 10 to 80 kGy, most preferably 20 to 60 kGy. Generallyspeaking, if the dose is less than 1 kGy, shaping may be difficult, andif the dose exceeds 100 kGy, the degradation of silicone rubber of themedical device which is an irradiation object is likely to occur.Although the irradiation of electron beams depends on the size (density)of the medical device as the irradiation object, if the medical deviceis relatively small, the irradiation of electron beams is performed onone side of the medical device. If the medical device is large, theirradiation of electron beams is performed on both sides of the medicaldevice or from multiple directions of the medical device. Thus, themedical device can be relatively uniformly irradiated with electronbeams.

The shaping of a part where properties of silicone rubber of the medicaldevice preferentially appear requires electron beam irradiation in thestatus where the part is given a bending angle approximately 5 to 6times an intentional bending angle. The magnification of the bendingangle (the increased bending angle relative to the desired bending anglein the final product) depends on the hardness of the silicone rubber andthe irradiation dose of electron beams.

For example, if silicone rubber is a cylindrical body such as a tube, ajig as a correcting body is a wire-like body, which body can be a copperwire whose surface is silver-plated. This copper wire is inserted intothe tube. The tube into which the copper wire is inserted issemi-circularly wound or bent around an another rod with a radius of 3mm and is formed into a U-shape. Electron beam irradiation is performedon the U-shaped tube into which the copper wire is inserted. After theirradiation, the copper wire is removed from the U-shaped tube, with theresult that a bending shape of about 30 degrees is left. Similarly, ifthe copper wire-inserted tube is wound or bent around the rod to beformed in a V-shape of about 135 degrees, a bending angle after theshaping is about 25 degrees. If an angle further smaller than 25 degreesis needed, the tube wound around the rod needs only to relieve theV-shaped bending. If a bending angle further greater than 30 degrees isneeded, the copper wire-inserted tube may be wound around the rod onetime (360 degrees), so that both ends of the rod may become linear.

Such shaping can be done by the same means as that for the tube even ifsilicone rubber is a wire-like body or a rod-like body. Similarly to thetube, the bending shape encountered during the electron beam irradiationdiffers from that encountered when the correcting member is removed.

Such a relationship can be set by an experiment.

If an irradiation dose of electron beam is equal to or greater than 10kGy (from ISO 11137), the same effect as electronic beam sterilizationcan be produced. Therefore, sterilization and shaping can concurrentlybe performed by irradiating electron beams to the medical devicepackaged together with the correcting member.

FIGS. 1-3 schematically illustrate examples of the medical device 10 andcorrecting member 20 according to one embodiment. The medical device 10and correcting member 20 together constitute a medical device assembly.As shown in FIG. 1, the medical device 10 is in the form of a tubularmember and possesses a through hole of a size and shape to receive thecorrecting member 20. In this illustrated embodiment, the distal end 14of the medical device 10 represents the predetermined portion of themedical device 10 which is subjected to electron beam irradiation. Atleast the distal end 14 (predetermined portion) of the medical device 10is comprised of silicone rubber.

The correcting member 20, which is made of a material which does notadhere, stick or cross-link to the silicone rubber upon contact of thecorrecting member with the predetermined portion of the medical device10, includes a portion (bent portion) 22 possessing a shape-giving bentshape. FIG. 1 illustrates that the bent portion 22 of the correctingmember 20, prior to being brought into contact with the predeterminedportion 14 of the medical device 10, is more bent than the predeterminedportion 14 of the medical device 10. The shape-giving shape of the bentportion 22 of the correcting member 20 is able to alter or change theshape of the predetermined portion 14 of the medical device 10 when thecorrecting member contacts the predetermined portion 14.

FIG. 2 illustrates the portion 22 of the correcting member 20 in contactwith the predetermined portion 14 of the medical device. Morespecifically, the correcting member 20 is positioned in the through hole12 in the medical device 10 so that the bent portion 22 of thecorrecting member axially overlaps the predetermined portion 14 of themedical device 10. Comparing FIGS. 1 and 2, the shape-giving shape ofthe bent portion 22 of the correcting member 20 alters or changes theshape of the predetermined portion 14 so the predetermined portion ofthe medical device 10 exhibits a shape different from the shape of thepredetermined portion 14 prior to contact with the correcting member 20.

After the correcting member 20 is in contact with the predeterminedportion 14 of the medical device as shown in FIG. 2, the predeterminedportion 14 of the medical device made of silicone rubber is electronbeam irradiated. Thereafter, as shown in FIG. 3, the correcting memberis moved out of contact with the medical device (the correcting memberis removed from the through hole in the tubular member 14). Thepredetermined portion 14 of the medical device now exhibits a shape thatis less bent than in the state shown in FIG. 2, but more bent than thestate shown in FIG. 1. Thus, the predetermined portion 14 of the medicaldevice, following electron beam irradiation and removal of thecorrecting member 20, possesses a shape intermediate the original shapeof the predetermined portion 14 of the medical device 10 (FIG. 1) andthe shape of the predetermined portion 14 when in contact andshape-influenced by the correcting member (FIG. 2). Similarly, thepredetermined portion 14 of the medical device, following electron beamirradiation and removal of the correcting member 20, possesses a shapeintermediate the original shape of the predetermined portion 14 of themedical device 10 (FIG. 1) and the shape of the bent portion 22 of thecorrecting member (FIG. 2).

The method, medical device and medical device assembly disclosed hereare described in detail with reference to specific embodiments discussedbelow.

First Embodiment

A tube having an external diameter of 4 mm and an internal diameter of 2mm was molded using silicone rubber SR-1554 (Shore A hardness 55±5) ofTigers Polymer Corporation. This molded article was cut into a length of10 cm. Copper wire whose surface is silver-plated, having a diameter of1.9 mm, was cut into a length of 10 cm, and was used as a shaping core.

Next, the core as a correcting member was inserted into the siliconerubber tube. The core-inserted tube was wound or bent around a rod-likebody to possesses a U-turn while centering the longitudinal-axialcentral portion thereof. The core-inserted tube was bent at 180 degrees.In this case, the central portion of the silicone rubber tube into whichthe core is inserted had a bending radius of 3 mm.

Next, Belgium IBA-made Rhodotron TT-200 was used as an electronirradiation apparatus to irradiate the bent tube with an electron beamof an irradiation energy of 10 MeV, a dose of 27.5 kGy from one side,and a dose of 27.5 kGy from the other side, 55.0 kGy in total.

Next, the core was removed from the bending tube, and thereafter thebending angle of the tube relative to the longitudinal axis thereof wasmeasured, with the result that it was 30 degrees.

Second Embodiment

The silicone rubber tube into which the core was inserted in the firstembodiment was hooked onto the rod-like body and bent in a V-shape at135 degrees with respect to the longitudinal axis. In this case, thecentral portion of the silicone rubber tube into which the core wasinserted had a bending radius of 3 mm.

Next, the same electron irradiation apparatus as in the first embodimentwas used to emit an electron beam at the bent tube under the sameconditions.

Next, after the core was removed from the bent tube, a bending anglerelative to the longitudinal axis of the tube was measured, with theresult that it was 25 degrees.

Comparative Examples 1 to 4

First and second comparative examples were obtained by the sameprocedures as in the first and second embodiments, respectively, withoutthe electron beam irradiation. The bent tubes after the removal of thecores (wires) had no bending tendency (i.e., the tube was no longer bentafter removing the core).

Third and fourth comparative examples were obtained by the sameprocedures as in the first and second embodiments, respectively, and bygamma beam irradiation in place of the electron beam irradiation. Benttubes after the removal of cores in the third and fourth comparativeexamples had no bending tendency.

Third Embodiment

A tube having an external diameter of 3.5 mm and an inner diameter of 2mm was molded using silicone rubber with the same grade number as in thefirst embodiment.

The tube was bent at 180 degrees with respect to a longitudinal axis byuse of the core similarly to the first embodiment.

Thereafter, the bent tube was irradiated with an electron beam in thesame procedure as in the first embodiment and the core was removed fromthe tube. The bending angle of the tube relative to the longitudinalaxis was measured, with the result that it was 32 degrees.

Fourth Embodiment

Similarly to the third embodiment, the silicone rubber tube of the thirdembodiment into which the core was inserted was subject to electron beamirradiation with the exception that it was bent at 135 degrees.

Next, after the core was removed from the bent tube, the bending angleof the tube with respect to the longitudinal axis was measured, with theresult that it was 23 degrees.

Comparative Examples 5 to 8

Fifth and sixth comparative examples were obtained by the sameprocedures as in the third and fourth embodiments, respectively, withoutthe electron beam irradiation. A silicone rubber tube bent at 180degrees had a bending tendency of as slight as three degrees after theremoval of the core. On the other hand, a silicone rubber tube bent at135 degrees had no bending tendency (i.e., the tube was no longer bentafter removing the core).

Seventh and eighth comparative examples were obtained by the sameprocedures as in the third and fourth embodiments, respectively, and bygamma beam irradiation in place of electron beam irradiation. Siliconerubber tubes after the removal of corresponding cores had slight bendingtendency.

Fifth Embodiment

A tube having an external diameter of 4.5 mm and an internal diameter of3 mm, made of silicone rubber 3×4.5CR (Shore A hardness 65 to 70) ofShin-Etsu Polymer Co., Ltd. was prepared.

The tube was bent at 180 degrees with respect to a longitudinal axis byuse of the core similarly to the first embodiment.

Thereafter, in the same procedure as in the first embodiment, the benttube was subjected to the electron beam irradiation and the core wasremoved therefrom. The bending angle of the tube relative to thelongitudinal axis thereof was measured, with the result that it was 33degrees.

Sixth Embodiment

A silicone rubber tube was subjected to electron beam irradiationsimilarly to the third embodiment with the exception that the siliconerubber tube of the fifth embodiment into which the core was inserted wasbent at 135 degrees with respect to the longitudinal axis.

Next, after the core was removed from the bent tube, the bending angleof the tube relative to the longitudinal axis was measured, with theresult that it was 24 degrees.

Comparative Examples 9 to 12

Ninth and tenth comparative examples were obtained by the sameprocedures as in the fifth and sixth embodiments, respectively, withoutthe electron beam irradiation. A silicone rubber tube bent at 180degrees had a bending tendency of as slight as four degrees after theremoval of the core. On the other hand, a silicone rubber tube bent at135 degrees had no bending tendency (i.e., the tube was no longer bentafter removing the core).

Eleventh and twelfth comparative examples were obtained by the sameprocedures as in the fifth and sixth embodiments, respectively, and bygamma beam irradiation in place of electron beam irradiation. Siliconerubber tubes after the removal of corresponding cores had slight bendingtendency.

Using silicone rubber having a Shore A hardness of 20, 35 and 50, thesame evaluation as the above embodiments and comparative examples wasperformed. This evaluation involved the bending angle, the presence orabsence of the electron beam irradiation and the gamma beam irradiationstudied in the first through sixth embodiments and the first throughtwelfth comparative examples. These studies show the same tendencies asthe embodiments and comparative examples described above regarding thepresence or absence of the electron beam irradiation. The aboveembodiments and comparative examples describe the use of silicone rubbertubes. By using, as a correcting member, a polypropylene-made trayhaving a groove corresponding to the intended shape-giving shape, asilicone rubber-made wire-shaped or rod-shaped body was fitted in thegroove and shaped by electron beam irradiation. Such shaping wasstudied. The results of this study show the same tendency as discussedabove.

A thin film cylindrical body such as a balloon is different, as below,from a catheter tube which is even the same cylindrical body. In a statein which the balloon is deflated, two blades, three blades or fourblades of the balloon are formed to project outwardly from the centralshaft of the balloon. A polypropylene sheet-made correcting member isinterposed among the blades. The correcting member and the blades arewound along the central shaft of the balloon or further, the blades arecovered from above (outside) by a correcting member or a thermalshrinking tube as a shape-fixation member. Then, they are subjected toelectron beam irradiation. In this way, the silicone rubber-made ballooncan be given the shape. Thus, the shape in the state of the balloon isdeflated can be given.

Incidentally, the Shore A hardness uses list values and the measurementvalues of TECLOCK Co., Ltd. made GS-719N “Type A Duro-meter.”

The detailed description above describes embodiments of the medicaldevice and manufacturing method disclosed here. The invention is notlimited, however, to the precise embodiment and variations described andillustrated above. Various changes, modifications and equivalents couldbe effected by one skilled in the art without departing from the spiritand scope of the invention as defined in the appended claims. It isexpressly intended that all such changes, modifications and equivalentswhich fall within the scope of the claims are embraced by the claims.

1. A medical device assembly comprising: a medical device possessing apredetermined portion comprising silicone rubber, the predeterminedportion possessing a first shape and being adapted to be electron beamirradiated to change the first shape of the predetermined portion andcause the predetermined portion to possess a predetermined shape; acorrecting member configured to contact the predetermined portion of themedical device to form a medical device assembly which is subject to theelectron beam irradiation, the correcting member being formed of amaterial which does not stick, adhere or cross-link to the siliconerubber when the correcting member contacts the medical device, thecorrecting member possessing a shape-giving shape which alters the firstshape of the predetermined portion of the medical device when thecorrecting member contacts the predetermined portion so thepredetermined portion of the medical device exhibits a second shapedifferent from the first shape, the correcting member being moved out ofcontact with the predetermined portion of the medical device after theelectron beam irradiation, whereupon the predetermined portion of themedical device possesses the predetermined shape which is different fromthe first shape and the second shape.
 2. The medical device assemblyaccording to claim 1, wherein the silicone rubber has a Shore A hardnessof 15 to 80 before electron beam irradiation.
 3. The medical deviceassembly according to claim 1, wherein the correcting member is a shapedwire body or shaped rod body.
 4. A medical device assembly comprising: amedical device comprising an electron beam-irradiated predeterminedportion made of silicone rubber, the electron beam-irradiatedpredetermined portion possessing a predetermined bent shape; acorrecting member out of contact with the predetermined portion of themedical device, the correcting member being previously in contact withthe predetermined portion of the medical device, the correcting memberbeing made of a material which does not adhere, stick or cross-link tothe silicone rubber during contact of the correcting member with thesilicone rubber of the predetermined portion even during electron beamirradiation of the correcting member and the silicone rubber, thecorrecting member which is out of contact with the predetermined portionof the medical device comprising a bending portion which possesses abent shape that is more bent than the predetermined bent shape.
 5. Themedical device assembly according to claim 4, wherein the medical deviceis a tubular member possessing a through hole.
 6. The medical deviceassembly according to claim 4, wherein the bending portion of thecorrecting member is at one end of the correcting member.
 7. The medicaldevice assembly according to claim 4, wherein the correcting member is ashaped wire body or shaped rod body.